Final answer:
The better deal for the client would be the percentage of invoice payout method as they would receive a higher amount compared to the fixed amount offered by the usual and customary fee payout.
Step-by-step explanation:
When comparing the payout methods of percentage of invoice and usual and customary fees, it is important to consider the specific amounts involved. In this case, the final invoice for the exploratory surgery is $2,000. With a percentage of invoice payout at 90%, the client would receive 90% of the $2,000, which is $1,800. On the other hand, with a usual and customary fee payout of $850, the client would receive a fixed amount of $850.
Comparing these two options, the percentage of invoice payout method would provide a better deal for the client in this scenario, as they would receive a higher amount compared to the fixed amount offered by the usual and customary fee payout.